They may have been wearing breast plates of painted tin and brandishing wooden swords, but the injuries were real.

One of the "centurions" who haunts the Colosseum suffered head injuries this week in a fight with a colleague outside the arena. A police officer said he found the man sprawled on the ground "with his face covered in blood".

Officers said the centurions were fighting over tourists' attention but colleagues disagree. "It's not true he was beaten. He just fell over and hurt himself," one of the gladiators said.

In January, Rome's head of archaeology announced plans to bring realistic gladiator fights back to the Colosseum, with swords, nets, tridents and daggers. Until then the ageing freelancers provide the only whiff of period atmosphere around the elliptical amphitheatre.

The last recorded violence was in 2007 when a gladiator assaulted two American tourists claiming they had not paid enough.